Red mulberry occurs in eastern North American forests. In Canada, it is only found in the Carolinian Zone (the small area of Ontario southwest of Toronto to Sarnia down to the shores of Lake Erie) near rivers, the shores of Lake Erie, and the slopes of the Niagara Escarpment. It is often found in areas where the forest canopy is quite open and allows lots of sunlight to reach the forest floor, but it will tolerate some shade.
Red Mulberry is considered endangered, and there are fewer than 300 red Mulberry trees remaining in Ontario. Red mulberry is hardy to sub-zero temperatures and is relatively hardy to drought, pollution, and poor soil, although its close relative, white mulberry, is hardier. Unfortunately, Red Mulberry is often outcompeted by the non-native White Mulberry and easily hybridizes with its relative, causing a loss of genetic purity in the native species. Mulberry leaves are the preferred food for silkworm caterpillars, which produce silk cocoons. Red Mulberry fruit is delicious and edible to humans when ripe and is quickly eaten by birds and small mammals in the summer.